Since the mid-nineteenth century, maps have helped elucidate the deadly mysteries of diseases like cholera and yellow fever. Yet today's global mapping of infectious diseases is considerably unreliable and may do little to inform the control of potential outbreaks, according to a new systematic mapping review of all clinically important infectious diseases known to humans.

Of the 355 infectious diseases assessed in the review, 174 showed a strong rationale for mapping and less than 5 percent of those have been mapped reliably. Unreliable mapping makes it difficult to fully understand the geographic scope and threat of disease and therefore make informed policy recommendations for managing it, write the authors of the study, which appears as open access on Feb. 4 in the journal Philosophical Transactions of the Royal Society B.

An online, open-access database, which accompanies the study, provides a quantitative scheme for evaluating the quality of data available for each infectious disease as well as specific mapping recommendations for each disease.

Among the recommendations for improving disease cartography are the use of new crowdsourcing techniques to gather data, such as analyzing the content and frequency of Twitter messages about disease. Twitter feeds during the 2009 H1N1 flu outbreak, for example, predicted outbreaks sooner than traditional disease surveillance methods.